FOOD, FACTS and FADS

Exploring the sense and nonsense of food and health


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Does the Mediterranean Diet Work? An Update

A previous post described the general results from the PREDIMED Study, a study that reported on the healthy benefits of a Mediterranean-type diet. See the previous post HERE. Now new results from a subset of volunteers from the same study gives us further insight into the way the Mediterranean diet may be heart healthy.

Researchers randomly chose 296 volunteers with a high risk of heart disease who had previously participated the PREDIMED STUDY. Each was assigned to one of the following three diets for one year:

  • A traditional Mediterranean diet with added 4 tablespoons of virgin olive oil per day
  • A traditional Mediterranean diet with an added handful of nuts per day
  • A healthy control that basically was a low fat diet (decreased red meat, sweets, processed food and high-fat dairy products)

Blood tests to measure high density lipoproteins (HDL) and low density lipoprotein (LDL) were conducted at the beginning and end of the study. For a more detailed discussion of the role of HDL and LDL as heart disease risks, see the information at the end of this post.

High levels of LDL or “bad” are linked to an increased risk of plaque formation in coronary arteries while high levels of HDL are linked to a decreased risk. LDL promotes atherosclerosis in arteries and HDL absorbs cholesterol and returns it to the liver for removal from the body. Therefore, its role helps to keep the blood vessels open.

Researchers think that it is not just the number of HDL particles that allegedly reduces the risk of heart disease, but its functional ability to do so, i e., how well does HDL work?

The results of this study showed only the control diet lowered total and LDL cholesterol as found in other studies. None of the diets improved HDL levels significantly; however, the Mediterranean diets both improved the functionality of the HDL significantly. Additionally, this benefit was much larger among those who given the diet with the extra amount of olive oil.

The Med Diets enhanced the functional ability of HDL by:

  • HDL removal of cholesterol from plaque in the arteries
  • Protected the process from LDL action on plaque development
  • Increased blood vessel relaxation to open blood flow.

One author concluded: “Following a Mediterranean diet rich in virgin olive oil could protect our cardiovascular health in several ways, including making our “good” cholesterol work in a more complete way.” The study was published in Circulation 135:633-643, 2017, a journal of the American Heart Association

Risk Factors for Heart Disease include:  High blood pressure, diabetes, obesity, and abnormal blood lipid levels as well as genetics, smoking activity, gender and age.  Some of these risk factors are modifiable by diet.

How are Lipids Transported in the Body?

The liver is the major lipid-producing organ. The liver uses excess protein and carbohydrate to make triglycerides or cholesterol. Triglycerides and cholesterol are carried to the cells by low-density lipoproteins (LDLs), the primary cholesterol delivery system for cells.

LDL’a must be taken up by cells by binding to an LDL receptor on the cell membrane surface or membrane. This binding allows LDLs to be removed from the blood and enter cells where they are broken apart to releases fats and cholesterol for the cell to use. If the amount of LDL cholesterol in the blood exceeds the amount that can be taken up by cells due to either too much LDL or too few receptors, the result is a high level of LDL cholesterol and high levels  are associated with an increased risk of heart disease

How is Cholesterol Eliminated?

Cholesterol cannot be broken down by the body so it must be returned to the liver to be eliminated.  This is accomplished by lipoproteins called high-density lipoproteins (HDLs.) HDLs are particles that originate in the intestinal tract and liver and pick up cholesterol and takes it to the liver for disposal if not needed. A high level of HDL decreases the risk of cardiovascular disease.

So the bottom line:

When you have blood work, the doctor may order blood tests that measures your total cholesterol, your LDL and HDL cholesterol to determine your individual risks of having heart disease in the future.

  • Total Cholesterol: Low risk <200; High risk >240
  • LDL Cholesterol: Low risk <100; High risk   >160
  • HDL Cholesterol: Low risk: > 60; High risk <40
  • Triglycerides: Low risk; <150; High risk >200

So you ideally want your LDL-C to be low and your HDL-C values to be as high as possible (more than likely dependent on diet and genetics. So think L means “lousy” and H means “healthy.”

 

 

 

 

 

 

 


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Can Food Be Medicine?

What a great program!!  It is interesting that feeding a person may cut health care costs in the long run. After some searching, it appears to be only in the Boston and Massachusetts area.  It may become a trend if the research indicates its benefits are cost effective. Another interesting fact is that the average age is stated at 49 “with a slew of chronic diseases” and they supposedly have a long waiting list.  Could the Standard American Diet (SAD) be a factor? Just a thought.

CLICK HERE.


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Diet Recommendations Update?

 

A good infograph at a glance tells us the latest information on the effects of these nutrition debates about diet and heart health. Click on the graphic in the article to enlarge the text of the infograph. As usual, these debates will continue; however, nutrition news constantly is subject to change based on additional knowledge from reputable research that will help clarify the sense from the nonsense. Bottom line: Diet decisions should be based on your own health records after consulting a reputable health care practitioner. Be aware and don’t fall for false health claims.

CLICK HERE.


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The Mediterranean Diet: Lower Health Care Costs?


The Mediterranean Diet Pyramid

The Mediterranean Diet is one of  the most “researched” diets of all time and has shown to have positive benefits  in respect to heart disease, cognitive health and cancer prevention. The following article is very interesting and presents an additional benefit  of changing the food culture in any country seeking to improve health care costs.

One promising change is to encourage healthy eating habits in  younger populations –  in this case, teenagers. Early nutrition education is of paramount importance for cultural change. This is where prevention of chronic diseases can make a startling difference. FYI: The Global Health Index of 163 countries ranked the U.S. #34. (Bloomberg, March 2017).

CLICK HERE.


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How the Food Industry Influences Nutrition Research

Industry funded studies are becoming a major influence on nutrition research that is already considered by some to have some important design limitations.

Headlines often proclaim that certain foods have healthy benefits not supported by science. These are used as marketing tools by the companies to describe their products in terms of what is described as a “health halo.” This practice contributes to false claims and the dissemination of nutrition misinformation which is already abundant.

One reason is that research in nutrition is not very well funded by very many sources; therefore, food companies often do provide the funds and at the same time gain their own benefits, i.e., increase their profits.

CLICK HERE.


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Do We Need Dietary Supplements?

March is National Nutrition Month. How ironic that the news this month includes the probability that Gwyneth Paltrow is initiating a new line of vitamin and mineral supplements. In the first place, do we really need another line of diet supplements?   I would also like to know just what are her credentials to offer the consumer any nutritional advice?

According to Dr. Paul Offit, author of Do You Believe in Magic? The Sense and Nonsense of Alternative Medicine,  clinical trials have shown no differences in the claimed beneficial effects versus placebo of the following popular supplements: Ginko biloba, St. John’s wort, garlic, saw palmetto, milk thistle, echinacea, or chondroitin sulfate.

CLICK HERE.


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Nutrition Research 101

Why is Nutrition Research so Difficult?

The Scientific Method 101

Ideally advances in nutrition are made using the scientific method. In case you can’t readily recall your last biology class, here it is in its most simple form:

  • The first step is to make an observation, e.g. more people get colon cancer in the U.S. than in Japan
  • Next, explanations are proposed and called a hypothesis, e.g. The lower incidence of colon cancer in Japan compared to the U.S. is due to diet differences.
  • To test the hypothesis, experiments are designed. Compare the diets and incidence of colon cancer in a Japanese American population compared to a U.S. Caucasian population.

If the results from  repeated experiments support the original hypothesis, a theory can be developed. if not, the hypothesis is rejected.

Simple, right? Not in nutrition. Why is nutrition information so confusing or contradictory? Here are some reasons why. This post only presents a few basic problems in nutrition research; it is not meant to be a comprehensive guide.

  1. You cannot keep people in a bubble.

Evidence-based nutrition should ideally be based on the randomized, placebo-controlled clinical trial using large population samples and extending the intervention for a reasonable time to measure health outcomes. Typically, one group is given a certain diet to follow; another group is given no particular diet but allowed to eat anything they choose. A randomized controlled trial (RCT) can provide sound evidence of cause and effect if the many variables are controlled.  These studies are just not practical for long-term nutrition interventions.  They are expensive long-term and have another important limitation. People are notorious for cheating on their assigned diets, and compliance is always difficult.

  1. Most nutrition information comes from observational studies.

Many nutritional studies are observational studies that attempt to assess how changes in diet affect health by looking at correlations or associations between what people report they eat and how many develop a particular disease.  When many observational studies reach the same conclusions, there is enough evidence to suggest  dietary recommendations. These types of studies only show correlation or associations, not cause and effect.

There is another problem with observational studies. They typically depend on surveys where people report what they ate the day (or week) before. This type of data reporting is known to be extremely unreliable. Researchers have long known that people misreport or forget, intentionally and unintentionally, what they eat.

 3. People and foods are different.

People obviously differ physiologically, psychologically, and genetically. This is shown in studies that measured people’s blood sugar responses to the same foods and found vast fluctuations. Also foods  differ in quality, content, preparation and other unknown characteristics, e.g. how they were grown or processed.

4. Conflict of interests and bias add to the confusion.

Food companies often try to conduct studies that promote the claimed health benefits of their products. They often use studies that support their claims as major marketing tools.

  1. Replication as part of the scientific method is often neglected.

There is always a chance that the original results may have occurred due to error. To alleviate this possibility, it is common if possible, to repeat the original experiment multiple times. This also is prudent when the original results are significant or surprising.

What Can You Do?

So, should you just give up on listening to anything about the food you eat? We should be reminded that “all scientific knowledge is subject to change. We learn from it.” We can learn from both negative results as well as positive results.

By looking at the big picture of  many studies (meta-analyses) and not just a few on a certain nutrition question, you can begin to see patterns that point to the same direction. It is extremely important to not dwell on single nutrient studies, but on studies that examine the total diet.

Pay attention to the source of funding and the potential biases of the authors. Do not pay attention to bold statements or scaremongering headlines that are not supported by the current research. Is it selling something? Is it based on someone’s personal story (anecdotal)?

Was the information interpreted accurately? Compare the news headlines with the peer-reviewed conclusions of the study information. Did the study discuss its limitations? Were the results or the conclusions of the study twisted in a way to support the bias of the author(s)? Has the importance of the study been exaggerated? Does it make sense?